The present invention is directed to a method of installing an underground pipe using a system. The system comprises a pilot horizontal directional drill, a pilot drill string having a first end and a second end, in which the first end is operatively connected to the pilot horizontal directional drill, and a product pipe section. The system further comprises an exit-side horizontal directional drill comprising a rotary spindle and a rotary motor coupled to the spindle. The method comprises the steps of rotating and advancing the pilot drill string to an exit point using the pilot horizontal directional drill, connecting the product pipe section to the spindle, and rotating the product pipe section using the spindle in order to connect the product pipe section to the second end of the pilot drill string, in which rotation of the spindle is driven by the motor. The method further comprises the steps pulling and rotating the product pipe section using the pilot horizontal directional drill, and simultaneously with the step of pulling and rotating the product pipe section, pushing the product pipe section into the ground with the spindle.
The present invention is also directed to a method of using a drilling system. The drilling system comprises a pilot drill, a pilot drill string having a first end and a second end, in which the first end is operatively connected to the pilot drill, and a drilling tool attached to the pilot drill string at its second end. The drilling system further comprises a product pipe attached to the drilling tool, and an exit-side drill. The exit-side drill comprises a spindle operatively connected to the product pipe, and a motor coupled to the spindle. The method comprises the steps of pulling and rotating the pilot drill string with the pilot drill, and pushing the product pipe with the exit-side drill while the spindle drives rotation of at least a portion of the motor.
The present invention is further directed to a method of using a horizontal directional drilling system. The system comprises an exit-side horizontal directional drill and a pilot horizontal directional drill. The exit-side horizontal directional drill comprises a rotationally-driven spindle coupled to a drill string, and a rotary motor coupled to the spindle. The motor is configured to operate in a first and second condition. The motor rotationally drives the spindle in the first condition and the spindle rotationally drives at least a portion of the motor in the second condition. The drill string is disposed between the exit-side horizontal directional drill and the pilot horizontal directional drill. The method comprises the steps of pulling and rotating the drill string with the pilot drill, and pushing the drill string with the exit-side horizontal directional drill while the motor is in the second condition.
Turning now to
In many drilling operations, the pilot bore 18 does not have a sufficient diameter for a product pipe. In these operations, a backreamer 20 may be attached to the distal end of the pilot drill string 14 at the exit point 16. The pilot drill 12 then retracts and rotates the pilot drill string 14. The backreamer 20 enlarges the pilot bore 18 to form an enlarged bore 22. The backreamer 20 may be attached to segments of product pipe 24. Thus, as the backreamer 20 is pulled back toward the pilot drill 12, the product pipe 24 is installed.
In large installation operations, a force required to enlarge the pilot bore 18 and pull the product pipe 24 may be significant. Further, the product pipe 24 is preferably attached in segments having complimentary threaded ends. A second, or exit side drill 30 located at the exit point 16 provides torque to connect new segments to the installed product pipe 24. The second drill 30 additionally provides thrust force to the product pipe 24 and therefore the backreamer 20. This force assists the pilot drill 12 in enlarging the pilot bore 18.
With reference to
The carriage 34 supports a spindle assembly 40. The spindle assembly 40 comprises a spindle 42 for connecting to and providing rotational force to the product pipe 24. The spindle assembly 40 further comprises a rotary motor 44 for rotating the spindle 42.
With reference to
A rotary brake 50 is disposed between the motor 44 and the gearbox 47. The brake 50 receives a rotational input and directly transfers the rotational input to the gearbox 47 through a rotating shaft. The brake 50 may comprise a pair of opposed brake shoes (not shown) that selectively engage the rotating shaft. When engaged, the brake shoes impart a frictional resistance to the rotating shaft, slowing rotation of the shaft. Continued application of the brake 50 without operation of the motor 44 will stop rotation of the spindle 42. When not engaged, rotation of the spindle 42 is unimpaired by the brake 50.
A mechanical disconnect 70 is provided between the brake 50 and the motor 44. The disconnect 70 allows the spindle assembly 40 of the second drill 30 to operate in a “free spin” mode. Because the pilot drill string 14, backreamer 20, and product pipe 24 (
A second disconnect 70a may be provided between a second motor 44a and the primary gearbox 49. Such a second disconnect 70a may be hydraulically linked to the disconnect 70 such that when one of the disconnects 70, 70a is in “free spin” mode, the other is as well. Further disconnects may be utilized if additional motors are likewise utilized.
With reference to
The output shaft 74 comprises a pinion 82 which is coupled through the brake 50 to the gearbox 47 (
The coupling 78 is located at an interface between the output shaft 74 and input shaft 72 of the disconnect. As shown, the output shaft 74 has a cavity 90 with internally disposed splines. The input shaft 72 has a pinion 92 with complementary splines. Geometric interfaces may likewise be used. Further, the coupling 78 may be formed with a pinion on the output shaft 74. In this configuration, the input shaft 72 would have a cavity.
The coupling 78 has two modes: an engaged mode and a disengaged mode. As shown in
A spring 108 disposed between the pinion 92 and the cavity 90 cushions the engagement between the input shaft 72 and output shaft 74.
When the coupling 78 is in engaged mode, rotation of the output shaft 48 of motor 44 is carried through the disconnect 70. This enables the spindle 42 to make up and break out sections of product pipe 24.
When the second drill 30 assists in pushing the product pipe 24, rotation is driven by the pilot drill 12. Thus, the coupling 78 is placed into disengaged mode. Any rotation of the product pipe 24 and spindle 42 is imparted to the output shaft 74 of the disconnect 70. However, as the coupling 78 is disengaged, the output shaft 74 rotates freely within the frame 71.
The disconnect 70 comprises a vent 110 to prevent pressure buildup due to rotation of the shafts 72, 74 or the movement of the output shaft 74 within the frame 71.
The disconnect 70 may be activated or deactivated from an operator console located on the second drill 30. Alternatively, the disconnect 70 may be operated remotely, or at the pilot drill 12.
Turning to
Unlike the spindle assembly 40, the spindle assembly 200 does not include a mechanical disconnect. Rather, the spindle 202 always remains coupled to the motor 208. Because a mechanical disconnect is not used, the motor 208 is configured to move between a first condition and a second condition. In the first condition, the motor 208 drives rotation of the spindle 202, allowing for makeup and breakout of the product pipe sections 24. In the second condition, the motor 208 is configured so that the spindle 202 may freely rotate without resistance from the motor 208. The drill string 14 and product pipe 24 may drive rotation of the spindle 202 when the motor 208 is in the second condition. Because the spindle 202 is still coupled to the motor 208, rotation of the spindle 202 by the drill string 14 and product pipe 24 causes the spindle 202 drive rotation of at least a portion of the motor 208.
Turning to
The crank shaft 216 is coupled to the gears 212. Thus, eccentric rotation of the crank shaft 216 powers rotation of the gears 212, which in turn rotate the spindle 202. The motor 208 is considered to be in the first condition when the crank shaft 216 drives rotation of the spindle 202.
In order for the motor 208 to stop driving rotation of the spindle 202 and. move to the second condition, the eccentricity of the crank shaft 216 is reduced to zero. To reduce the eccentricity of the crank shaft 216 to zero, the pistons 220 are extended equally and are hydrostatically balanced against the eccentric element 218. Additionally, the crank shaft 216 is moved so that is centered within the eccentric element 218. A hydraulic cylinder (not shown) may move the crank shaft 216 within the eccentric element 218. Such operations may take place in response to a command signal sent to a controller within the motor 208.
Once the eccentricity of the crank shaft 216 is reduced to zero, the crank shaft 216 may be turned externally without any resistance from the pistons 220. The crank shaft 216 can thus be turned by the rotating spindle 202, via the gears 212, without damaging the motor 208. The motor 208 is considered to be in the second condition when the spindle 202 is able to drive rotation of the crank shaft 216. Thus, the motor 208 is switched into neutral in the second condition.
While the crank shaft 216 is being turned externally when the motor 208 is in the second condition, motor displacement shifting above zero may cause pressure to build in the pistons 220. This would cause resistance in the drill string 20 and possible damage to tile motor 208 and hydraulics. Preferably, an operator of the spindle assembly 200 would be alerted to this condition to determine the cause and remedy the issue.
To return the motor 208 to the first condition, a command signal may be sent to the controller within the motor 208. Such signal may direct the crank shaft 216 to move back to an eccentric position and the pistons 220 to again retract and extend at different times. The motor 208 may be moved between tile first and. second condition, as needed, during operation of the second drill 30.
Changes may be made in the construction, operation and arrangement of the various parts, elements, steps and procedures described herein without departing from the spirit and scope of tile invention as described in the following claims. For example, a control system may be used to actuate each coupling or decoupling event, or a mechanical lever may be used. A hydraulic actuator is described, but other suitable actuators may be used.
Number | Date | Country | |
---|---|---|---|
62791358 | Jan 2019 | US | |
62438134 | Dec 2016 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 16738027 | Jan 2020 | US |
Child | 17838402 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 15853156 | Dec 2017 | US |
Child | 16738027 | US |